Manual:Configuring file uploads

MediaWiki supports uploading and integration of media files.
This page describes the technical aspects of this feature, see Manual:Image administration and Help:Images for general usage information.

Starting from MediaWiki version 1.1, uploads are initially disabled by default, due to security considerations.
Uploads can be enabled via a configuration setting, although it is recommended that you check certain prerequisites first.

Prerequisites

Make sure uploads are enabled in PHP

If this is not set, PHP scripts cannot use the upload functions, and MediaWiki's uploads will not be enabled.

If the open_basedir directive is set, it must include both the destination upload folder in your MediaWiki installation ("{$IP}/images") and the 'upload_tmp_dir' folder (default system folder if not set).
The addition of the 'upload_tmp_dir' can avoid messages like "Could not find file "/var/tmp/php31aWnF" (where in this example the 'upload_tmp_dir' is '/var/tmp').
Read more about PHP file uploads at File upload basics and in particular move_uploaded_file().

Note: The formal value for the variable is a boolean expression.
PHP treats each string not recognized as a False value as true, hence the often used "on" value yields the same result.

Check for Windows and IIS users

Set %SystemRoot%\TEMP to have permissions for the Internet Guest Account (IUSR_MachineName, or IUSR for IIS 7+): Read, write and execute;

Check directory security

The upload directory needs to be configured so that it is not possible for an end user to upload and execute other scripts, which could then exploit access to your web directory and damage your wiki or web site.

Set the /images folder (or the /uploads folder in previous versions) to have permission "755":

User can read, write and execute;

Group can read and execute;

World can read and execute.

Only the folders must have executable permissions. Files must not have the executable permission.

If using safe_mode, make sure the directory is owned by the user used for running the php script (that is, the apache user or, in case of suphp, the script owner).

sudo chown -R www-data:www-data images/

If using CentOS 6 or Mageia the owner:group in the chown command should be "apache:apache" instead of "www-data:www-data".

If using SELinux, make sure to adjust the ACLs accordingly (see there).

If using suphp, make sure the umask is set to 0022 (or less) in /etc/suphp.conf.

Restrict directory listing on images folder

If you don't want a public user to list your images folder, an option is to set this up in your apache configuration:

<Directory/var/www/wiki/images>Options -Indexes
</Directory>

Check .htaccess file

The images directory in the MediaWiki installation folder contains an .htaccess file with some configurations on it.
The goal of this file is to make the upload folder more secure, and if you place your upload directory somewhere else, it's recommended to also copy the .htaccess file to the new location, or apply that configuration on the server directly.
However, some of those configurations may cause conflicts or errors, depending on how the server is configured.

Some things to take into account:

If the server doesn't allow to set or override directives in .htaccess files, accessing any file under that folder may result in a generic "HTTP 500 error". If that's the case, you should comment-out the lines, and apply those directives directly on the server configuration files. The directives that are most likely causing the problems are AddType —which prevents HTML and PHP files from being served as HTML—, and php_admin_flag —which would prevent PHP files from being parsed and executed on the server as such.

Before MediaWiki 1.27, if you have a custom 404 handler to generate thumbnails with the thumb.php script, the rewrite rules in this .htaccess file may disable previous rules, because it lacks the RewriteOptions inherit option (task T67220).

# Add new types to the existing list from DefaultSettings.php$wgFileExtensions[]='docx';$wgFileExtensions[]='xls';$wgFileExtensions[]='pdf';$wgFileExtensions[]='mpp';$wgFileExtensions[]='odt';$wgFileExtensions[]='ods';

However, certain file extensions are blacklisted ($wgFileBlacklist) and cannot be uploaded even if added to $wgFileExtensions.
To upload files with blacklisted extensions, you must modify the blacklist.
For instance, to allow users to upload executables:

Thumbnailing

If the file is not visual (like an Image or Video) a fileicon is used instead.
These are generated by the iconThumb() function in the File class in the FileRepo group.
Icons stored in "$wgStyleDirectory/common/images/icons/" in a "fileicon-$extension.png"-format.

Set maximum size for file uploads

post_max_size and upload_max_filesize in php.ini

By default, the configuration code in php.ini limits the size of files to be uploaded to 2 megabytes (and the maximum size of a post operation to 8 megabytes).
To allow uploading of larger files, edit these parameters in php.ini:

This may require root access to the server.
(If you are on a shared host, contact your server administrator.)

If you are increasing the maximum upload filesize to a value greater than 100MB, you will need to add $wgMaxUploadSize with the new upload filesize value to LocalSettings.php.

Locating the php.ini file

Typical location in which php.ini may be found.

The location of the php.ini file varies on the distribution you are using.
(Try "locate php.ini" or "php -i" to find the location of your config file.)
[1]

It is important to change the php.ini file in the apache2 folder.
For example, there may be a core default php.ini at /etc/php5/cli/php.ini as well as one at /etc/php5/apache2/php.ini.
If you are using mod_php (most common), the most likely location for the correct php.ini file is in /etc/php5/apache2 or /etc/php/7.0/apache2.
For php-fastcgi, edit /etc/php5/cgi/php.ini.

Multiple websites hosted on a server

If you have more than one website hosted on a server and want to change only for Mediawiki, insert into your /etc/apache2/sites-enabled/your_wiki_site.com inside <Virtual Host>:

php_value upload_max_filesize 100M
php_value post_max_size 100M

Both above settings also work in a .htaccess file if your site uses mod_php.
If your site uses PHP >= 5.3 and allows it, you can place php.ini directives in .user.ini files instead.

web server limits

Your web server may impose further limits on the size of files allowed for upload.
For Apache, one of the relevant settings is LimitRequestBody.
[2] For Nginx, client_max_body_size is the relevant setting.[3] For Lighttpd, server.max-request-size is what may need modification.[4]

After editing your php.ini or web server configuration, you will need to restart Apache or IIS.

Ubuntu 16.04: sudo service apache2 restart

You may also need to restart php5-fpm after altering your PHP (or ngingx server?) configuration.

(sudo /etc/init.d/php5-fpm restart in Linux, for example.)

uploading too large of files warning

MediaWiki itself issues a warning if you try to upload files larger than what is specified by $wgUploadSizeWarning option.
This is independent of the hard limit imposed by PHP.

temporary upload limits

Temporary changes to upload limits (when using multiple wikis on a farm, for example) can be altered by adding the lines:

ini_set('post_max_size','50M');ini_set('upload_max_filesize','50M');

to the MediaWiki LocalSettings.php configuration file for each wiki.
In this example the PHP limit is set at 50 Mb.
Note that these settings will not override the maximum settings set above (since the core php.ini and apache2 php.ini files set the absolute maximum).
This method sets maximums that are less than the absolute maximum.

IIS7 upload limit

By default, IIS7[5] on Windows 2008 allows only 30MB to be uploaded via a web application. Larger files will return a 404 error after the upload. If you have this problem, you can solve it by increasing the maximum file size by adding the following code to <system.webServer> in the web.config file:

With the above maxAllowedContentLength, users can upload files that are 50,000,000 bytes (50 MB) in size.
This setting will work immediately without restarting IIS services.
The web.config file is located in the root directory of your web site.

In the IIS web.config file, override the value of maxRequestLength.
For example, the following entry in web.config allows files that are less than or equal to 2 gigabytes (GB) to be uploaded:

<httpRuntime maxRequestLength="2097151" executionTimeout="18000"/>

With IIS 7, you also need to configure it to allow large uploads.
This is found by clicking “Request Filtering > Edit Feature Settings” in the IIS section in the middle of the window.
Set the ”Maximum allowed content length (Bytes)” field to 2147482624.
If you don’t see "Request Filtering" in the IIS section, it needs enabled via Internet Information Services > World Wide Web Services > Security in the "Turn Windows features on or off" area in Control Panel.

If the above tip does not enable large uploads, then open a command prompt and execute this command as well:

Allowing Java JAR Uploads

By default, MediaWiki will scan all uploads that appear to be ZIP archives and reject any that contain Java .class files.
This is a security measure to prevent users uploading a malicious Java applet.
For non-public sites only, use the following to disable this check:

$wgAllowJavaUploads=true;

This setting can be used as a work around for allowing mimetypes to be accepted indiscriminately.
For example, if you attempt to upload a .doc file created by Word 2007, no matter the ext list you provide and mimetype checking you invoke or prohibit, you will receive the message:

The file is a corrupt or otherwise unreadable ZIP file. It cannot be properly checked for security.

.doc files saved by Word 2007 (and possibly later versions) contain a small embedded ZIP archive storing metadata that is not representable in the binary .doc format as used by earlier versions of Word.
This embedded ZIP data confuses the Java archive scanner, causing the .doc file to be rejected.
Files in the newer .docx file format are valid ZIP archives in their entirety, and can be uploaded successfully without setting $wgAllowJavaUploads.

Uploading directly from a URL ("Sideloading")

If you want to allow a user to directly upload files from a URL, instead of from a file on their local computer, set $wgAllowCopyUploads = true.

By default, upload by URL are only possible using the API (or extensions such as UploadWizard).
To make the option usable from Special:Upload, you need to set $wgCopyUploadsFromSpecialUpload to true as well.
On the upload form, you will then see an additional field for the URL, below the usual filename field.
The URL field is greyed out per default, but can be activated by activating the radiobutton (checkbox) to the left of the field.

In order to use this feature, users must have the user rightupload_by_url.
This right was granted to sysops by default until MediaWiki 1.20 but it now needs to be granted explicitly.
To allow this to normal users, set

$wgGroupPermissions['user']['upload_by_url']=true;

Keep in mind that allowing uploads directly from an arbitrary location on the web makes it easier to upload random, unwanted material, and it might be misunderstood as an invitation to upload anything that people might come across on the web.

PHP's cURL support must be enabled to support this feature. Configure your PHP when installing using the --with-curl option.

If your server is accessing internet through a proxy then $wgHTTPProxy needs to be set accordingly. Either you supply it directly or, if your server supplies the environment variable "http_proxy" see your phpinfo(), then you could use the following code in your LocalSettings.php:

/* * Proxy to use for CURL requests. */if(isset($_ENV['http_proxy']))$wgHTTPProxy=$_ENV['http_proxy'];

Undeleting images

Undeleting images is possible as an option since MediaWiki 1.8, and enabled by default since MediaWiki 1.11.

Upload directory

An article in the file namespace with the name of the file, e.g. File:MyPicture.png. This page is stored and can be edited like any other page.

The file itself is stored into the folder on the file system, which is configured in $wgUploadDirectory or into one if its subfolders (see below).

If necessary and thumbnailing is available, thumbnailed versions of the file will be created when necessary (such as for the usage on the file description page. These are stored in the thumb directory of the image directory, in a separate directory for each main file.

If $wgHashedUploadDirectory is set to true, uploaded files will be distributed into sub-directories of $wgUploadDirectory based on the first two characters of the md5 hash of the filename. (e.g. $IP/images/a/ab/foo.jpg)
Creation of such subdirectories is handled automatically.
This is used to avoid having too many files in one folder because some filesystems don't perform well with large numbers of files in one folder.

If you only maintain a small wiki with few uploaded images, you could turn this off by setting $wgHashedUploadDirectory = false, all images are uploaded in $wgUploadDirectory itself. (e.g. $IP/images/foo.jpg)

Multiwiki sites

Make sure you've changed the site location in LocalSettings.php from, e.g. /var/lib/mediawiki to wherever your installation is, and created a writeable images directory (most of the rest can be symlinked).

Not doing so will mysteriously break image uploads.

Configuring the upload form

The upload form message provided with the default MediWiki installation (which appears when you click "Upload file" link or go to Special:Upload link) may not go very well for you.

Edit MediaWiki:Upload-default-description to add an initial text to the "Summary" field of your upload form (for example your wiki site has a universal template for upload summaries and you want everyone to use that template).

Known problems on Windows

Running MediaWiki on Windows server has some restrictions in allowed filenames, due to a PHP bug.
PHP can't handle filenames with non-ascii characters on it correctly, and MediaWiki will refuse to upload files containing such characters to prevent broken uploads (task T3780), with the message This wiki does not support filenames with special characters..

Since MediaWiki 1.31 MediaWiki can handle filenames with non-ascii characters if it's using PHP 7.1 or later.

Known problems with database names having non-alphanumeric characters

If $wgDBname contains non-alphanumeric characters, uploads may fail with errors like Could not create directory "mwstore://local-backend/local-public/<path>"..
This is caused by an internal check for valid container name for file backend, but it's constructed using $wgDBname.